Rune had tried to apply the scientific knowledge from his previous life to increase the power of his Fireball spell.
Unfortunately, the spell behaved like a rigidly fixed program — utterly immutable, resisting even the slightest alteration.
He did not give up.
He had never forgotten the skill-upgrade panel that had come with him.
It remained his sole path to breaking through.
In the end, he chose to place [Fireball] into that single, irreplaceable skill slot.
Even though it was a cantrip so basic it barely qualified as 0th-Tier, he had no other choice.
When he carefully “dragged” the runic image of [Fireball] from his mind toward the central slot—
Buzz—
A faint vibration, perceptible only to him, emanated from the slot. The simple icon of Fireball locked into place, its edges glowing with the pale blue light that signified “Permanently Bound.”
The entire panel seemed to receive its first infusion of energy. It brightened subtly, and a line of text appeared at the bottom:
[Fireball]
[Level: 1]
[Experience: 0/100]
[Available EXP:0]
The road had opened.
If Fireball could be leveled up, then the remaining question was simple: how to gain the experience required.
Skills did not advance for free.
They required experience.
According to the prompt, experience came from hunting “monsters” in the game sense — but this world obviously had no creatures with floating health bars.
The method of gaining experience became the new puzzle.
Until one chance encounter.
While assisting the village butcher as usual, a captured Slywind Rabbit — ferocious and not yet fully dead — suddenly thrashed and lunged at him.
This was a 0th-Tier magical beast: blindingly fast, with incisors capable of gnawing through bone. On pure instinct, Rune channeled nearly half his available mana into the then-feeble, tennis-ball-sized fireball and forced it directly into the creature’s open mouth.
Enduring the agony of the rabbit’s tearing bite, he burned the dying beast alive from the inside out.
The moment it perished, the system panel in the lower-right corner of his vision jumped clearly: [System Alert!]
[Target Defeated: High-Tier 0 Slywind Rabbit]
[Experience Gained: 25]
The Fireball entry changed from [Lv1: 0/100] to [Lv1: 25/100].
In that instant, it was as if lightning had split open the fog.
Rune understood.
The “monsters” were right here — the magical beasts that roamed this world.
From that moment onward, every future plan crystallized with perfect clarity.
Hunt magical beasts → gain experience → level up Fireball → gain greater combat power → hunt stronger beasts → gain more experience → continue leveling Fireball → increase combat power → gain even more experience…
From then on, every waking moment he burned with the urge to charge deep into the forest and begin his hunt-and-upgrade cycle.
But he forcibly suppressed the impulse.
His reason never stopped reminding him: he was still a “trash” mage who could only cast Fireball. The village would never permit him to risk himself alone.
More critically — a Level 1 Fireball was laughably weak. Using it to hunt magical beasts was tantamount to suicide.
He had to wait. He had to endure.
He had to strengthen this feeble spark first, prove he could protect himself, before anyone would allow him near real danger.
So he poured every spare second into practicing control over the pitiful mana output of Level 1 Fireball, while methodically — and very cautiously — exploring the outermost edges of the forest, studying the habits of the lowest-tier magical beasts.
Until one month ago.
By helping the butcher process captured, injured, but still-living low-tier beasts, he finally accumulated enough experience to push [Fireball] to Level 2.
BOOM!
The change was immediate and exhilarating.
At Level 1, the fireball was only apple-sized, its flames loose and dull red. Beyond five meters from his hand, the light would flicker erratically; even a light breeze could knock it off course.
Casting it consumed 50 mana points, and maintaining it demanded constant output. Control was crude — either cradle it in the palm for light or hurl it like a rock. No finesse. Virtually no damage potential.
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At Level 2, the base form doubled in size — roughly two apples in diameter.
That visible “growth” filled Rune with genuine excitement.
Yet even in the midst of that thrill, his rationality remained razor-sharp.
He knew perfectly well that a mere increase in quantity — larger flame volume, greater mana allocation — was far from enough.
The true destructive power of fire lay in temperature.
Without sufficient heat, even the largest fireball was nothing more than a clumsy flare or ignition source — incapable of delivering instant, lethal damage.
Regrettably, rough tests using ignition points and color changes of various materials showed that the core temperature of a Level 2 Fireball still hovered around 300°C — no meaningful leap from Level 1.
This led him to a sobering realization: magical flame in this world operated differently from the combustion he knew before. Adding more burning material did not automatically raise the temperature.
It behaved as though the gods themselves had imposed a hard cap: 300°C, no more.
Rune sank into deep contemplation.
He understood clearly: flame magic’s damage came from heat. Volume was irrelevant; temperature was everything.
Yet here, the spell had simply grown larger without delivering the decisive temperature spike — or any other extreme offensive property — needed to shift the balance.
In a world of transcendent power, 300°C was a “stable” but underwhelming temperature. Against thick-skinned magical beasts it might singe fur or blister skin, but it lacked the penetration for deep burns or fatal wounds.
In short: his Fireball had leveled up, but he still lacked the combat strength to hunt magical beasts.
Still, Rune refused to yield.
Drawing on his previous life’s scientific framework, he calmly dissected the fundamental differences between Level 1 and Level 2 Fireball, searching for other vectors of improvement.
Through repeated testing and rigorous analysis, he gradually identified the two core enhancements the system bestowed upon leveling the skill:
First: a linear increase in energy scale.
Level 1 allowed a fixed “one-apple” volume of stable flame. Level 2 doubled it to “two apples.” This meant the baseline output of fire-element — the total mana convertible into flame — had doubled.
Second: a dramatic leap in control precision.
At Level 1, he could only generate and sustain the fireball; output was fixed — palm-cradle or simple throw. No shape alteration. Level 2 granted basic shaping capability — the ability to modify the spell’s geometric model.
Now he could shift the flame between rough spheres, flattened discs, or simple rods. While shape changes alone offered negligible direct damage increase — fire’s killing power always traced back to temperature — the underlying implication was profound.
Having isolated the core upgrade modules, real thinking began.
“Shape alteration is merely superficial…” One month ago, by the riverbank during an experiment, Rune stared at the orange flame shifting at his will and realized, “…what truly matters is that this ‘shaping ability’ grants me finer intervention over mana output pathways and the spell model’s structure.”
This newfound control authority, combined with the doubled energy budget, pointed toward a potential breakthrough.
“I must increase temperature…” The thought was crystal clear. He dredged up knowledge from his previous life. “Flame is plasma… temperature depends on particle density and collision frequency…”
A spark ignited in his mind.
“Wait… density?”
The idea flared.
Level 2 had given him a higher mana ceiling and finer flame manipulation.
What if, instead of maintaining a “larger” form, he kept the original volume… and forced more mana and fire-element into that same space?
“Compression…” he murmured, eyes growing brighter. “Increase density! Higher density means exponentially greater particle collisions per unit volume… temperature must skyrocket!”
“Since I can now control shape… can I compress the volume, raise internal density, and thereby elevate core temperature?” The hypothesis formed almost instantly.
The logic chain unfolded cleanly:
Level 2 provided “two-apple” worth of fire-element.
Level 1’s baseline form was “one-apple” volume.
He now controlled twice the total fire-element mass.
If he forcibly constrained that doubled quantity back into the original one-apple volume… what would happen?
Basic thermodynamics supplied the answer: in a near-enclosed system, increasing molecular count dramatically raises pressure and collision frequency, sharply elevating temperature.
In his previous world, flame was a high-temperature plasma — a soup of molecules, atoms, electrons, and ions colliding violently in confined space, releasing energy as heat and light. More particles, higher density, more frequent collisions, more violent energy release, higher temperature.
By analogy, in this world the “fire-element” that composed magical flame — whatever its exact nature — might follow similar energy-release principles:
In the same spatial volume, more fire-element particles should yield higher energy density, and therefore higher manifested temperature.
“Leveling Fireball to 2 isn’t just about doubling size…” Clarity flooded Rune’s mind. “…it’s doubling the total controllable energy — the ‘fuel’ supply! Temperature is the direct expression of energy density! The key is whether I can use the new control precision to achieve compression — to cram more fuel into a smaller combustion chamber!”
In the days that followed, after finishing daily chores and basic mana meditation, Rune devoted every free moment to this dangerous, pivotal “compression experiment.”
He chose remote riverbank areas to minimize fire risk.
And the experiment continued… right up to today, one month later.
He had attempted the compression trial 79 times.
Still, no success.
…
“Could it be… that once a spell is manifested, its form — like the burning state of magical flame — becomes fixed by the world’s rules? Immutable afterward?”
Reflecting on the recent explosion, Rune voiced the hypothesis.
But he immediately shook his head.
“No. There must be a way to change it! Magic in this world can be altered through technique — I simply haven’t discovered the correct method yet.”
“If spell manifestation were a completely rigid, standardized process, my chantless casting would never have succeeded!”
“Therefore, magic can be modified by subjective will… I just need to find the mechanism!”
“As long as I uncover that mechanism, my concept becomes feasible!”
Rune was a profoundly confident man.
He knew — with absolute certainty — that his theory was sound.
He never wavered. He was convinced he would succeed.
He simply required… a little luck… and one flash of insight.
He calmed himself and carefully reviewed the process of the 79th trial, along with every previous attempt.
He searched meticulously for the breakthrough path.
These 79 experiments had not all been safe.
Far from it.
Early attempts were riddled with setbacks and danger: uneven mana injection caused structural instability and premature dispersal into sparks; excessive compression force triggered small-scale mana backlash, leaving his arm numb and mind stinging; poor control let the constrained fireball rampage like a trapped beast in his palm.
Yet he endured through sheer tenacity.
Each failure deepened his microscopic understanding of mana manipulation and honed his focus and precision.
Gradually, he tamed what was once an unstable Level 2 fireball under even slight compression — making it docile, almost gentle.
Just as it had been today: even under his pressure, it maintained only a steady, heartbeat-like rhythm — no sign of imminent rupture.
Yet despite reaching an extremely high degree of control, he still could not compress the fireball.
Not even slightly.
He could sense that the internal fire-element density was more than sufficient to support compression.
But it refused to yield.
He did not understand why.
“Why? I clearly possess enough control authority to reshape the form — which means I should be able to force this ‘large’ fireball back down to the original ‘small’ size!”
“How can it be so difficult? Not even the slightest progress?”
Rune dissected every detail of the experiments in his mind.
“If the fire-element inside is the fuel sustaining combustion, then the outer layer of fire-element — combined with my mental force — forms the combustion chamber model. All I need to do is shrink the chamber… wait!”
Rune stood motionless, eyes closed, brain racing at full throttle.
Then—
His eyes snapped open.
A flash of excitement crossed his gaze.
“Model? Spell model? That’s it!”
